includes/Interwiki.php

   1 <?php
   2 /**
   3  * @file
   4  * Interwiki table entry
   5  */
   6
   7 /**
   8  * The interwiki class
   9  * All information is loaded on creation when called by Interwiki::fetch( $prefix ).
  10  * All work is done on slave, because this should *never* change (except during schema updates etc, which arent wiki-related)
  11  */
  12 class Interwiki {
  13
  14         // Cache - removes oldest entry when it hits limit
  15         protected static $smCache = array();
  16         const CACHE_LIMIT = 100; // 0 means unlimited, any other value is max number of entries.
  17
  18         protected $mPrefix, $mURL, $mLocal, $mTrans;
  19
  20         function __construct( $prefix = null, $url = '', $local = 0, $trans = 0 )
  21         {
  22                 $this->mPrefix = $prefix;
  23                 $this->mURL = $url;
  24                 $this->mLocal = $local;
  25                 $this->mTrans = $trans;
  26         }
  27
  28         /**
  29          * Check whether an interwiki prefix exists
  30          *
  31          * @return bool Whether it exists
  32          * @param $prefix string Interwiki prefix to use
  33          */
  34         static public function isValidInterwiki( $prefix ){
  35                 $result = self::fetch( $prefix );
  36                 return (bool)$result;
  37         }
  38
  39         /**
  40          * Fetch an Interwiki object
  41          *
  42          * @return Interwiki Object, or null if not valid
  43          * @param $prefix string Interwiki prefix to use
  44          */
  45         static public function fetch( $prefix ) {
  46                 global $wgContLang;
  47                 if( $prefix == '' ) {
  48                         return null;
  49                 }
  50                 $prefix = $wgContLang->lc( $prefix );
  51                 if( isset( self::$smCache[$prefix] ) ){
  52                         return self::$smCache[$prefix];
  53                 }
  54                 global $wgInterwikiCache;
  55                 if ($wgInterwikiCache) {
  56                         $iw = Interwiki::getInterwikiCached( $prefix );
  57                 } else {
  58                         $iw = Interwiki::load( $prefix );
  59                         if( !$iw ){
  60                                 $iw = false;
  61                         }
  62                 }
  63                 if( self::CACHE_LIMIT && count( self::$smCache ) >= self::CACHE_LIMIT ){
  64                         reset( self::$smCache );
  65                         unset( self::$smCache[ key( self::$smCache ) ] );
  66                 }
  67                 self::$smCache[$prefix] = $iw;
  68                 return $iw;
  69         }
  70
  71         /**
  72          * Fetch interwiki prefix data from local cache in constant database.
  73          *
  74          * @note More logic is explained in DefaultSettings.
  75          *
  76          * @param $prefix \type{\string} Interwiki prefix
  77          * @return \type{\Interwiki} An interwiki object
  78          */
  79         protected static function getInterwikiCached( $prefix ) {
  80                 $value = self::getInterwikiCacheEntry( $prefix );
  81
  82                 $s = new Interwiki( $prefix );
  83                 if ( $value != '' ) {
  84                         // Split values
  85                         list( $local, $url ) = explode( ' ', $value, 2 );
  86                         $s->mURL = $url;
  87                         $s->mLocal = (int)$local;
  88                 }else{
  89                         $s = false;
  90                 }
  91                 return $s;
  92         }
  93
  94         /**
  95          * Get entry from interwiki cache
  96          *
  97          * @note More logic is explained in DefaultSettings.
  98          *
  99          * @param $prefix \type{\string} Database key
 100          * @return \type{\string) The entry
 101          */
 102         protected static function getInterwikiCacheEntry( $prefix ){
 103                 global $wgInterwikiCache, $wgInterwikiScopes, $wgInterwikiFallbackSite;
 104                 static $db, $site;
 105
 106                 wfDebug( __METHOD__ . "( $prefix )\n" );
 107                 if( !$db ){
 108                         $db = dba_open( $wgInterwikiCache, 'r', 'cdb' );
 109                 }
 110                 /* Resolve site name */
 111                 if( $wgInterwikiScopes>=3 && !$site ) {
 112                         $site = dba_fetch( '__sites:' . wfWikiID(), $db );
 113                         if ( $site == "" ){
 114                                 $site = $wgInterwikiFallbackSite;
 115                         }
 116                 }
 117
 118                 $value = dba_fetch( wfMemcKey( $prefix ), $db );
 119                 // Site level
 120                 if ( $value == '' && $wgInterwikiScopes >= 3 ) {
 121                         $value = dba_fetch( "_{$site}:{$prefix}", $db );
 122                 }
 123                 // Global Level
 124                 if ( $value == '' && $wgInterwikiScopes >= 2 ) {
 125                         $value = dba_fetch( "__global:{$prefix}", $db );
 126                 }
 127                 if ( $value == 'undef' )
 128                         $value = '';
 129
 130                 return $value;
 131         }
 132
 133         /**
 134          * Load the interwiki, trying first memcached then the DB
 135          *
 136          * @param $prefix The interwiki prefix
 137          * @return bool The prefix is valid
 138          * @static
 139          *
 140          */
 141         protected static function load( $prefix ) {
 142                 global $wgMemc, $wgInterwikiExpiry;
 143                 $key = wfMemcKey( 'interwiki', $prefix );
 144                 $mc = $wgMemc->get( $key );
 145                 $iw = false;
 146                 if( $mc && is_array( $mc ) ){ // is_array is hack for old keys
 147                         $iw = Interwiki::loadFromArray( $mc );
 148                         if( $iw ){
 149                                 return $iw;
 150                         }
 151                 }
 152
 153                 $db = wfGetDB( DB_SLAVE );
 154
 155                 $row = $db->fetchRow( $db->select( 'interwiki', '*', array( 'iw_prefix' => $prefix ),
 156                         __METHOD__ ) );
 157                 $iw = Interwiki::loadFromArray( $row );
 158                 if ( $iw ) {
 159                         $mc = array( 'iw_url' => $iw->mURL, 'iw_local' => $iw->mLocal, 'iw_trans' => $iw->mTrans );
 160                         $wgMemc->add( $key, $mc, $wgInterwikiExpiry );
 161                         return $iw;
 162                 }
 163
 164                 return false;
 165         }
 166
 167         /**
 168          * Fill in member variables from an array (e.g. memcached result, Database::fetchRow, etc)
 169          *
 170          * @return bool Whether everything was there
 171          * @param $res ResultWrapper Row from the interwiki table
 172          * @static
 173          */
 174         protected static function loadFromArray( $mc ) {
 175                 if( isset( $mc['iw_url'] ) && isset( $mc['iw_local'] ) && isset( $mc['iw_trans'] ) ){
 176                         $iw = new Interwiki();
 177                         $iw->mURL = $mc['iw_url'];
 178                         $iw->mLocal = $mc['iw_local'];
 179                         $iw->mTrans = $mc['iw_trans'];
 180                         return $iw;
 181                 }
 182                 return false;
 183         }
 184
 185         /**
 186          * Get the URL for a particular title (or with $1 if no title given)
 187          *
 188          * @param $title string What text to put for the article name
 189          * @return string The URL
 190          */
 191         function getURL( $title = null ){
 192                 $url = $this->mURL;
 193                 if( $title != null ){
 194                         $url = str_replace( "$1", $title, $url );
 195                 }
 196                 return $url;
 197         }
 198
 199         function isLocal(){
 200                 return $this->mLocal;
 201         }
 202
 203         function isTranscludable(){
 204                 return $this->mTrans;
 205         }
 206
 207 }